BAKERSFIELD (CBS SF/AP) — A Bakersfield police officer shot and killed an unarmed 73-year-old man with dementia as he stood in a neighbor’s driveway, authorities in California said.

The officer was responding a report of a man with a gun, but no gun was found and the man’s family said he was in the early stages of dementia.

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The Kern County coroner said in a statement that the man, 73-year-old Francisco Serna, was declared dead at the scene at about 1:15 a.m. on Monday.

Police Sgt. Gary Carruesco told the Los Angeles Times that police had arrived at about 12:30 a.m. and when a witness pointed to Serna, one officer fired several rounds and killed him.

Carruesco said no gun was found in a search of the scene.

Serna’s son, Rogelio Serna, told the Los Angeles Times that his father didn’t own a gun. He said his father was retired and a grandfather.

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“My dad did not own a gun. He was a 73-year-old retired grandpa, just living life,” Rogelio Serna told the Times. “He should have been surrounded by family at old age, not surrounded by bullets.”

Rogelio Serna said his father had worked at a cotton gin in California’s Central Valley until retiring about a dozen years ago.

He said his father had been suffering from delusions and other early signs of dementia that had appeared to be getting worse in the past month. His father often took late-night walks alone to tire himself out, he said.

Police had visited the house twice before because his confused father activated a medical alarm, Rogelio Serna said.

The coroner said an autopsy would be performed on Francisco Serna.

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